Method for manufacturing oxide layer capable of reducing gradient of side wall

Abstract

The invention provides a method for manufacturing an oxide layer capable of reducing the gradient of a side wall. In the prior art, silicon oxide is directly subjected to photoetching and wet etching without being washed with hydrofluoric acid buffer corrosive liquid so as to result in larger gradient of the side wall. The method comprises the following steps: firstly, growing the silicon oxide on a silicon substrate through thermal oxidation process; secondly, washing the silicon oxide by using the hydrofluoric acid buffer corrosive liquid, and drying the silicon oxide; thirdly, coating photoresist on the silicon oxide, and baking the photoresist; fourthly, forming a graph of the oxide layer on the photoresist by exposure process; fifthly, developing the graph; sixthly, etching the graph by using the hydrofluoric acid buffer corrosive liquid to form the oxide layer; and finally, removing the photoresist. The method effectively reduces the compactness of the surface of the oxide layer and the adherence force of the oxide layer with the photoresist by washing the silicon oxide with the hydrofluoric acid buffer corrosive liquid before the photoetching and the wet etching processes, thereby effectively reducing the gradient of the side wall, and effectively improving the performance of a device.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an oxide layer manufacturing method capable of reducing the slope of sidewalls. Background technique [0002] Silicon oxide is one of the most widely used insulating dielectrics in the field of semiconductor manufacturing. It can be used as field oxide layer, gate oxide layer and shallow trench isolation structure (STI), etc. Silicon oxide can be produced by thermal oxidation and chemical vapor deposition. Process production, the thermal oxidation method is suitable for places that require high insulation performance, such as making field oxide layers and gate oxide layers. [0003] In the manufacturing process of semiconductor devices, in order to improve the breakdown characteristics of the devices, some devices need to form a thicker (more than 2 micron) field oxide layer (Field Oxide) on the silicon substrate for isolation. The manufacturing method of the oxide lay...

AI Technical Summary

Problems solved by technology

When the field oxide layer is manufactured, the slope of the side wall is an important parameter. When the slope of the side wall is large, for example, when the angle between it and the silicon substrate reaches 30 degrees, it will affect the subsequent active area (Active area). Area (referred to as AA area), such as deposition or ion implantation process, etc., which affect the performance of the device

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